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An interview with a Republican mayor, James Brainard on city level climate action is presented. Topics discussed include views on personal or political reasons to participate in the issue of climate change; policies on global carbon emissions; and climate-change impacts on sea level in coastal areas and forest fires in other regions.

The article presents the author's views on the biggest and the most neglected threat to humanity, global warming. The implications of subsequent climate change require special attention in industrialized countries. Climate change's most felt effects are rising sea levels, resource depletion, freshwater shortages, and deforestation. It mentions that the periodical issue focuses on the dimensions of environmental security and their impact on international politics.

There is growing respect for and recognition of te ao Mäori within Aotearoa's environmental policy and management space. However, to ensure that Aotearoa can build a better future equitably a 'tika transition' must be realised, whereby iwi, hapü and Mäori (the rangatiratanga sphere) and the Crown (kawanatanga sphere) exist within distinct and equal political entities, with the rangatiratanga sphere leading and governing tikanga and mätauranga Mäori policy and legislation. We examine two prominent environmental issues - sea level rise and taonga species protection - facing iwi, hapü, Mäori and the Crown, exploring the barriers, solutions and positive steps towards a 'tika transition' in each area. We recommend that policy and legislation include stronger instruments for shared decision making and specific funding for iwi, hapü and mana whenua to strengthen the rangatiratanga sphere. It is acknowledged that the barriers and solutions are interconnected and will rely on good relationship building and trust, power sharing and knowledge sharing, and policy and legislation that allows for and supports the rangatiratanga sphere as its own distinct space for tikanga-based governance and jurisdiction. [ABSTRACT FROM AUTHOR]

The article discusses how a fragile glacier in an isolated part of Antarctica could cause a catastrophic rise in global sea levels, known as the ‘Doomsday Glacier,' a wedge of fast flowing ice pouring into the ocean off the Antarctic coast to the south-west of Chile. It reports because the glacier is also being melted by warm water washing beneath it, the more that it melts, the faster it flows, exacerbating the problem and transforming more of what once had been ice into new ocean.

The article presents a study examining the late-Holocene Epoch sea level based on a reconstruction from a salt marsh in the Malltraeth estuary in North Wales. Information is provided on how the research can inform modeling of past and future relative sea-level changes in the British Isles.

As temperatures and sea levels rise, among other issues, environmental change is becoming an increasingly important driver of both internal and external migration across the globe. The loss of livelihood that these changes engender, and will increasingly cause in the coming decades, is forcing larger and larger numbers of individuals and groups to seek opportunities in other areas. As this phenomenon becomes more prevalent, it is imperative that communities, governments, NGOs, and other interested parties put in place policies to mitigate and adapt. This paper looks at the intersection of environmental change and migration. More specifically, it discusses the changing climate and environment and then looks at how this will, and already is, affecting migration patterns around the world. It then will provide a number of guiding principles for policymakers, academics, and others to think about when dealing with this issue. [ABSTRACT FROM AUTHOR]

Faced with potentially staggering human and economic costs, governments around the world are beginning to plan and implement adaptive measures designed to stem the effects of climate change. Some of these adaptations will likely benefit certain property owners and communities at the expense of others. For example, seawalls intended to save valuable parcels of land from sea-level rise could wind up forcing seawater onto neighboring parcels that would not have flooded otherwise. One day in the not-too-distant future, societies will have to grapple with the question of whether the government is responsible for harms it causes in its attempts to save livelihoods and land threatened by climate change. This Note seeks to address that question by analyzing the extent to which a government in the United States would face takings liability if its adaptive measures to address sea-level rise—one of the most salient property harms that will result from climate change—save certain parcels but harm others. Despite a long line of case law under which the government is liable for a taking when it intentionally floods private property, this Note concludes that, under certain circumstances, climate change adaptations could present the type of emergency situation that American courts have frequently held exempts the government from takings liability. This Note nonetheless argues that broader government takings liability may lead to more efficient and equitable climate change adaptation. It also considers some undesirable outcomes that could result from broader government takings liability and discusses potential solutions to minimize those problems. [ABSTRACT FROM AUTHOR]

Louisiana lost nearly 5,000 km2 of its coastal land area due to relative sea level rise (including local, regional, and global factors driving relative sea level change) since 1932, mirroring both the hazards associated with sea level rise and the time horizons of sea level rise impacts expected this century. This represents an opportunity to examine the relationship between long-term population changes and shoreline change. Based on detailed land change data for the period 1932–2010 and a small area population estimation technique for the period 1940–2010, we examine intra-parish population changes in relation to shoreline changes for the one million plus residents living in the ten coastal parishes of Louisiana. We find that since 1940, only two of the ten coastal parishes exhibited landward population movement, which we define as movement perpendicular to the shoreline, exceeding 1 km. Three parishes exhibited seaward population movement in excess of 1 km. Overall, we find very little net intra-parish landward population movement for the region. Our findings suggest that coastal Louisiana's historical population has not moved in concert with observed shoreline encroachment. We also find a potential tipping point related to population migration when a neighborhood loses at least 50% of its land area. Our findings suggest that this lack of landward population movement could be attributable to either localized adaptation strategies or migrations to other landward areas. [ABSTRACT FROM AUTHOR]

In coming decades, sea level rise associated with climate change will make some communities uninhabitable. Managed retreat, or planned relocation, is a proactive response prior to catastrophic necessity. Managed retreat has disruptive health, sociocultural, and economic impacts on communities that relocate. Health impacts include mental health, social capital, food security, water supply, sanitation, infectious diseases, injury, and health care access. We searched peer-reviewed and gray literature for reports on small island or coastal communities at various stages of relocation primarily due to sea level rise. We reviewed these reports to identify public health impacts and barriers to relocation. We identified eight relevant small communities in the USA (Alaska, Louisiana, and Washington), Panama, Fiji, Papua New Guinea, Solomon Islands, and Vanuatu. Affected populations range from 60 to 2700 persons and are predominantly indigenous people who rely on subsistence fishing and agriculture. Few reports directly addressed public health issues. While some relocations were successful, barriers to relocation in other communities include place attachment, potential loss of livelihoods, and lack of funding, suitable land, community consensus, and governance procedures. Further research is needed on the health impacts of managed retreat and how to facilitate population resilience. Studies could include surveillance of health indicators before and after communities relocate due to sea level rise, drought, or other environmental hazards. Lessons learned may inform relocation of both small and large communities affected by climate change. [ABSTRACT FROM AUTHOR]

This article presents a decadal transition from a decreasing trend to an increasing trend in the late 1990s for autumn rainfall in central China. The atmospheric and oceanic background underlying this regime shift is also addressed. Accompanying the above decadal transition, the moisture convergence and ascending motion averaged in central China both switch from a weakening trend to a strengthening trend. Meanwhile, after the late 1990s, the declining of the Asian sea level pressure (SLP) and the deepening of the Lake Balkhash trough may induce more cold air from high latitudes to break out southward. The strengthening of the low-level southerly in East Asia could transport more moisture northward from low latitudes. More cold air and more warm-moist airflow encountering in the targeted region contribute to the increasing trend of local rainfall. The situation before the late 1990s is generally reversed, which accounts for the decreasing trend of autumn rainfall. The movement of the East Asian jet (EAJ) from southward to northward also has a contribution via its influence on dynamic condition. Additionally, changes in the sea surface temperatures (SSTs) in the western Indian and Atlantic Oceans from a cooling trend to a warming trend in the late 1990s play significant roles through their modulations on moisture transport and cold-air activities. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Sediment grain sizes of a South China Sea core reveal paleoenvironment change from 36 kyr BP. • High sea levels promoted (impeded) the ∼0–2 μm (∼15–100 μm) component. • Low sea level and favorable topography close to estuary caused a layer of turbidite. • The ∼2–10 μm component records climate changes dominated by the East Asian monsoon. Abstract Sediment grain size is an important proxy to detect sedimentary process and record paleoenvironmental variations in continental slopes. Grain size measurements were performed for 298 samples of the 5.96-m-long core PC338 spanning the past 36 kyr recovered from the northern South China Sea (SCS). Results show that sea level and climatic influences on grain size distributions are crucial. A turbidite formed during the Last Glacial Maximum (LGM) is ascribed to the favorable topography close to the Red River estuary induced by the low sea level. Four end-member (EM) components for the normal sediment layers were unmixed using a lognormal parametric end member modeling (EMM). With the sea level decreasing, more EM4 (∼15–100 μm) and less EM1 (∼0–2 μm) supplied the SCS slope. Because EM2 (∼2–10 μm) consisted of fluvial suspension is dominated by the East Asian summer monsoon (EASM) precipitation, it has the potential to substitute for the EASM intensity. EM2 varied in-phase with many south China paleoclimate records and the 30°N July insolation over the past 36 kyr, and cooling climate events (including the LGM, Heinrich events H1 and H3, Younger Dryas, 8.2 ka and 10.3 ka) lowered the EM2 content. Our results further confirm the synchronous EASM evolution in the South China continent mainly forced by the Northern Hemisphere summer insolation. [ABSTRACT FROM AUTHOR]

Abstract A primary goal of geomorphology is to infer from topographic form the processes that drive landscape evolution. Often implicit is the assumption that orogen-scale (> 10 10 m2 planform area) transient landscape changes on Earth are driven by equally large-scale transient tectonics, climate, or sea level. Here we argue that meso-scale (105–1010 m2) uplift perturbations may affect landscapes on scales that far exceed their size and duration. We study the consequences of transient variations in uniform surface uplift that are localized in space, such as may occur in volcanic landscapes or during landslide emplacement. These localized uplift perturbations define a class of landforms that are larger than typical hillslope lengths but smaller than orogens, and grow at rates that are rapid compared to fluvial bedrock erosion. We use 1D and 2D landscape evolution models to show that uplift perturbations drive transient lateral migration and vertical amplification of nearby ridges, sometimes generating a spatially distributed imbalance between uplift and erosion that causes plateau-like topography. Relaxation to steady-state conditions, in which erosion balances uplift everywhere, depends on the degree to which wave-like adjustment within channels or of ridges dominates subsequent landscape erosion. We find that the spatial structure and timescales of landscape response are predictable given uplift perturbation parameters. In 2D models, localized uplift generates a radial pattern of channel network and drainage divide reorganization that remains long after the perturbation is eroded. The spatial pattern of ridges and channels in a landscape thus may record both the scale and pace of perturbations to the uplift field. Highlights • Transient, localized uplift perturbations drive large-scale landscape response. • Nearby ridges are focused towards localized uplift and are transiently amplified. • Distributed erosion imbalances drive transient plateau formation and drainage capture. • Topographic steady state is easily and permanently disrupted by uplift perturbations. • Transient divide migration speed depends both on hillslope and fluvial processes. [ABSTRACT FROM AUTHOR]

The article offers the information on several topics including the information that if greenhouse gas emissions remain high, global average sea level could rise by nearly eight feet by 2100 and 50 feet by 2300. The article mentions about the new analysis of epidemiological data for the first time show that there are adverse long-term effects of human health related to ozone.

Abstract Grain size, clay mineralogy, 87Sr/86Sr, εNd, and AMS14C analyses of deep-sea sediments cored in the central Bay of Bengal are used to reconstruct the evolution of provenances and climate control since the last glacial period. Clay minerals, 87Sr/86Sr ratios and εNd values indicate a mixture of sediment from the Himalaya source, Indian Peninsula and Indo-Burman Ranges/Irrawaddy River. These analyses show that the Himalaya Mountains and Indo-Burman Ranges/Irrawaddy River are the main suppliers before the Holocene period, while the inputs of erosion materials from the Indo-Gangetic floodplain and the Indian Peninsula increase during the Holocene period, accompanied by reduced inputs of the Indo-Burman Ranges and Irrawaddy sediments. The regional "source-sink" process is significantly controlled by the climate. Warm and wet climate conditions and enhanced Indian monsoon intensity during the Holocene period are responsible for the increase of sediment input from the Indo-Gangetic Plain and the Indian Peninsula by improving erosion in the source area, input from the floodplain to the river channel and the intensity of the southwest monsoon current. In contrast, due to the decrease of the northeast monsoon current during the Holocene period, sediment input from the Irrawaddy and Indo-Burman Ranges are constrained. Deposition center transition between the submarine fan and shelf during the last glacial period and the Holocene period occurs in response to the sea level change, which controls the sedimentary mode and thus significantly influences the transportation and deposition processes in the Bay of Bengal (BoB). [ABSTRACT FROM AUTHOR]

Seasonal variations of sea level have an important impact on coastal groundwater level and salinity. Consequently, they cause spatiotemporal changes in the seawater/freshwater interface. The oceanic tide effect on groundwater dynamics and salinity was investigated in the coastal aquifers of Sahel Doukkala, Morocco. Continuous monitoring of water level and electrical conductivity (EC) was carried out in two coastal wells (drawing from two different aquifers) over a period of 9 months. The main objective of the study was to characterize the aquifers’ exposure to anthropic pumping operations and oceanic tide oscillations. The obtained results showed that oceanic tide has a significant effect on groundwater level as well as on water salinity. The fluctuation periods of groundwater level and tidal level were found to be equal, with a specific time lag. Hydraulic diffusivity was calculated using both confined- and semi-confined-aquifer methods and by analyzing both the time lag and amplitude damping factor. Results indicate hydraulic diffusivity differences between the two aquifers. In addition, there were apparent differences depending on whether time lag or amplitude was analyzed, possibly due to effects of heterogeneity within the aquifers. A detailed study of water EC variation revealed the significant influence of daily and synodic tide on groundwater salinity. Water EC variations were significant when hydraulic diffusivity is higher, indicating that sea-level oscillations induce freshwater/seawater interface movement and consequently influence the groundwater quality. [ABSTRACT FROM AUTHOR]

Differentiating the impacts of climate change between 1.5°C and 2°C requires a regional and sector-specific perspective. Whereas for some regions and sectors the difference in climate variables might be indistinguishable from natural variability, other areas especially in the tropics and subtropics will experience significant shifts. In addition to region-specific changes in climatic conditions, vulnerability and exposure also differ substantially across the world. Even small differences in climate hazards can translate into sizeable impact differences for particularly vulnerable regions or sectors. Here, we review scientific evidence of regional differences in climate hazards at 1.5°C and 2°C and provide an assessment of selected hotspots of climate change, including small islands as well as rural, urban, and coastal areas in sub-Saharan Africa and South Asia, that are particularly affected by the additional 0.5°C global mean temperature increase. We interlink these with a review of the vulnerability and exposure literature related to these hotspots to provide an integrated perspective on the differences in climate impacts between 1.5°C and 2°C. [ABSTRACT FROM AUTHOR]

Inner shelf to shelf-margin delta and slope-fan deposits in the Cenozoic Pearl River Mouth Basin in the northern continental margin of the South China Sea comprise the most important petroleum reservoirs in the basin and their evolution reflects a changing interplay of tectonics, sea level change and sediment supply. Integrated analysis of 3D seismic, well logs and core data allows interpretation of depositional architecture and evolution of the delta systems as they responded to the major controls. Inner shelf-delta systems, sited on the landward reaches of the continental margin, are characterized by thickly stacked distributary channel, thin (20-40 m) but relatively coarse delta-front and thin, fine-grained, distal delta to prodelta deposits. In contrast, outer shelf to shelf-margin deltaic systems formed 200 m (merging outwards to 1000 m) high clinoforms with steep slopes imaged on 3D seismic profiles as S-shape or tangential progradational reflections. Slumps and debris flow as well as sandy turbidite slope-fan deposits are common on the slopes of the clinoforms. Basinward and landward, cross-shelf transits of the delta systems are evident, as they formed some 18–20 stacked, high-frequency transgressive-regressive deltaic cycles (0.8–3 Myr) and five megacycles (3 to 10 Myr). Development of the deltaic cycles is interpreted as the result of high-amplitude sea level falls and rises related to glacio-eustasy as well as to changing sediment supply. The large-scale transgressive-regressive evolution of the deltaic clastic wedge is likely to have been controlled mainly by long-term changes in tectonic subsidence rate and sediment supply. The shelf-edge deltaic regressions are likely to have developed during sea level fall, but also during periods of high sediment input enhanced by uplifted tectonic relief and catchment enlargement or at times by monsoonal intensification events. [ABSTRACT FROM AUTHOR]

The article comments on sea level rise. Topics discussed include the projected variation in global mean sea level (GMSL) increase, the use of tide gauge and satellite altimetry in measuring sea levels, and the concept of local sea level variations. Information on the contribution of melting land-ice in Antarctica and Greenland to sea level rise is also given.

This paper presents a system to perform large ensembles climate stochastic forecasts. The system is based on random analogue sampling of sea-level pressure data from the NCEP reanalysis. It is tested to forecast an NAO index and the daily average temperature in five European stations. We simulated 100 member ensembles of averages over lead times from 5 days to 80 days in a hindcast mode, i.e. from a meteorological to a seasonal forecast. We tested the hindcast simulations with usual forecast skill scores (CRPSS or correlation), against persistence and climatology. We find significantly positive skill scores for all time scales. Although this model cannot outperform numerical weather prediction, it presents an interesting benchmark that could complement climatology or persistence forecast. [ABSTRACT FROM AUTHOR]

Although most seagrasses inhabit subtidal areas, a few species occur in the intertidal zone. The seagrass, Zostera japonica Asch. & Graebn., is an intertidal seagrass species, and thus this species may be vulnerable to environmental changes associated with sea level rise due to climate change. We examined the effects of continuous submergence conditions, which might be caused by sea level rise, on the growth of the intertidal seagrass, Z. japonica. In the present study, submerged conditions were generated in a Z. japonica meadow in the intertidal zone using transparent cylindrical cores, and the growth responses to the inundation conditions were examined. Daily photon flux density and temperature were not significantly different between the manipulated submerged and the control intertidal conditions during the experimental period. Increases in shoot height, biomass, and leaf productivity were among the acclimatory responses of Z. japonica to the inundation conditions. Shoot density, however, decreased rapidly in the submerged conditions as a result of the self-shading induced by taller and larger shoot sizes. Thus, prolonged inundation, which would be induced by a rise in sea level, had both positive and negative effects on the growth of the intertidal seagrass, Z. japonica, which exhibited plasticity at the individual and population levels. According to the results of our study, the restricted distribution of Z. japonica in the intertidal zone may not be a consequence of tidal inundation stress in the subtidal zone. [ABSTRACT FROM AUTHOR]

Abstract: Sea‐level rise (SLR) impacts on intertidal habitat depend on coastal topology, accretion, and constraints from surrounding development. Such habitat changes might affect species like Belding's savannah sparrows (Passerculus sandwichensis beldingi; BSSP), which live in high‐elevation salt marsh in the Southern California Bight. To predict how BSSP habitat might change under various SLR scenarios, we first constructed a suitability model by matching bird observations with elevation. We then mapped current BSSP breeding and foraging habitat at six estuarine sites by applying the elevation‐suitability model to digital elevation models. To estimate changes in digital elevation models under different SLR scenarios, we used a site‐specific, one‐dimensional elevation model (wetland accretion rate model of ecosystem resilience). We then applied our elevation‐suitability model to the projected digital elevation models. The resulting maps suggest that suitable breeding and foraging habitat could decline as increased inundation converts middle‐ and high‐elevation suitable habitat to mudflat and subtidal zones. As a result, the highest SLR scenario predicted that no suitable breeding or foraging habitat would remain at any site by 2100 and 2110. Removing development constraints to facilitate landward migration of high salt marsh, or redistributing dredge spoils to replace submerged habitat, might create future high salt marsh habitat, thereby reducing extirpation risk for BSSP in southern California. [ABSTRACT FROM AUTHOR]

The effects of abrupt changes in slope angle and orientation on turbidity current behavior have been investigated in numerous physical and numerical experiments and examined in outcrop, subsurface, and modern systems. However, the long-term impact of subtle and evolving seabed topography on the stratigraphic architecture of deep-water systems requires fine-scale observations and extensive 3-D constraints. This study focuses on the Permian Laingsburg and Fort Brown formations, where multiple large sand-rich systems (Units A-F) have been mapped from entrenched slope valleys, through channel-levee systems, to basin-floor lobe complexes over a 2500 km2 area. Here, we investigate three thinner (typically <5 m in thickness) and less extensive sand-rich packages, Units A/B, B/C, and D/E, between the large-scale systems. Typically, these sand-rich units are sharp-based and topped, and contain scours and mudstone clast conglomerates that indicate deposition from high-energy turbidity currents. The mapped thickness and facies distribution suggest a lobate form. These distinctive units were deposited in similar spatial positions within the basin-fill and suggest similar accommodation patterns on the slope and basin floor prior to the larger systems (B, C, and E). Stratigraphically, these thin units represent the first sand deposition following major periods of shut-down in sediment supply, and are interpreted as marking a partial re-establishment of sand delivery pathways creating "disconnected lobes" that are fed mainly by flows sourced from failures on the shelf and upper slope rather than major feeder channel-levee systems. Thickness and facies patterns throughout the deep-water stratigraphy suggest seabed topography was present early in the basin formation and maintained persistently in a similar area to ultimately form a stepped slope profile. The stepped slope profile evolved through three key stages of development: Phase 1, where sediment supply exceeds deformation rate (likely caused by differential subsidence); Phase 2, where sediment supply is on average equal to deformation rate; and Phase 3, where deformation rate outpaces sediment supply. This study demonstrates that smaller systems are a sensitive record of evolving seabed topography and they can consequently be used to recreate more accurate paleotopographic profiles. [ABSTRACT FROM AUTHOR]

Understanding the history, causes, and impact of sea-level changes is a challenge for our societies that face accelerated global sea-level rise. In this context, improvement of our knowledge of sea-level changes and shoreline migration at geological time scales is critical. The preserved, laterally correlative sedimentary record of continental erosion on passive margins has been used to reconstruct past sea level. However, the detailed nature of a basic clinothem progradational pattern observed on many of these margins is still poorly known. This paper describes the sedimentary facies and interprets the depositional environments and the architecture of the clinothems of the New Jersey shelf (offshore northeastern USA) to depict the origin and controls of the distribution of the sediment on the margin. We analyze 612 cores totaling 1311 m in length collected at three sites 60 km offshore Atlantic City, New Jersey, during International Ocean Discovery Program-International Continental Scientific Drilling Program (IODP-ICDP) Expedition 313. The three sites sampled the lower to middle Miocene passive margin sediments of the New Jersey shelf clinothems. We also collected wireline logs at the three sites and tied the sedimentary architecture to the geometry observed on seismic profiles. The observed sediment distribution in the clinoform complex differs from that of current models based on seismic data, which predict a progressive increase in mud and decrease in sand contents in a seaward direction. In contrast, we observe that the clinoforms are largely composed of muds, with sands and coarser material concentrated at the rollover, the bottomset, and the toe of the slope. The shelf clinothem topsets are storm-influenced mud whereas the foreset slope is composed of a mud wedge largely dominated by density current deposits (e.g., low-density turbidites and debrites). The architecture of the clinothem complex includes a composite stack of ~30-m-thick clinothem units each made up of four systems tracts (Transgressive, Highstand, Forced-Regressive, and Lowstand Systems Tract) building individual transgressiveregressive sequences. The presence of mud-rich facies deposited during highstands on the topset of the clinoform, 40-60 km offshore from the sand-prone shoreface deposit (observed in the New Jersey onshore delta plain), and the lack of subaerial erosion (and continental depositional environments) point to a depositional model involving a subaerial delta (onshore) feeding a distant subaqueous delta. During forced regressions, shelf-edge deltas periodically overstep the stacks of flood-influenced, offshore-marine mud wedges of the New Jersey subaqueous delta, bringing sand to the rollover and building up the large-scale shelf-prism clinothems. The clinothem complex develops on a gently dipping platform with a ramp-like morphology (apparent dip of 0.75°-0.5°) below mean storm wave base, in 30-50 m of water depth, 40-60 km seaward of the coastal area. Its shape depends on the balance between accommodation and sedimentation rates. Subaqueous deltas show higher accumulation rates than their subaerial counterparts and prograde three times further and faster than their contemporaneous shoreline. The increase in the intensity of waves (height and recurrence intervals) favors the separation between subaqueous and subaerial deltas, and as a consequence, the formation of a flat topset geometry, a decrease in flood events and fluvial discharge, an overall progressive decrease in sediment grain size (from sequence m5.45, ca. 17.8-17.7 Ma, onwards), as well as an increase in sedimentation rates on the foresets of the clinoforms. All of these are recognized as preliminary signals that might characterize the entry into the Neogene icehouse world. [ABSTRACT FROM AUTHOR]

For now, the question about future sea level change in the Mediterranean remains a challenge. Previous climate modelling attempts to estimate future sea level change in the Mediterranean did not meet a consensus. The low resolution of CMIP-type models prevents an accurate representation of important small scales processes acting over the Mediterranean region. For this reason among others, the use of high resolution regional ocean modelling has been recommended in literature to address the question of ongoing and future Mediterranean sea level change in response to climate change or greenhouse gases emissions. Also, it has been shown that east Atlantic sea level variability is the dominant driver of the Mediterranean variability at interannual and interdecadal scales. However, up to now, long-term regional simulations of the Mediterranean Sea do not integrate the full sea level information from the Atlantic, which is a substantial shortcoming when analysing Mediterranean sea level response. In the present study we analyse different approaches followed by state-of-the-art regional climate models to simulate Mediterranean sea level variability. Additionally we present a new simulation which incorporates improved information of Atlantic sea level forcing at the lateral boundary. We evaluate the skills of the different simulations in the frame of long-term hindcast simulations spanning from 1980 to 2012 analysing sea level variability from seasonal to multidecadal scales. Results from the new simulation show a substantial improvement in the modelled Mediterranean sea level signal. This confirms that Mediterranean mean sea level is strongly influenced by the Atlantic conditions, and thus suggests that the quality of the information in the lateral boundary conditions (LBCs) is crucial for the good modelling of Mediterranean sea level. We also found that the regional differences inside the basin, that are induced by circulation changes, are model-dependent and thus not affected by the LBCs. Finally, we argue that a correct configuration of LBCs in the Atlantic should be used for future Mediterranean simulations, which cover hindcast period, but also for scenarios. [ABSTRACT FROM AUTHOR]

This study models shoreline retreat due to sea level rise by using geographic data and applies the model to future projections of decreases in beach area for 806 beaches in Japan. The model uses a foreshore slope (angle) based on data from a digital elevation model, and influence of the present simplified method for estimation of the shoreline retreat is examined through comparisons with previous studies at typical locations. The proposed method gives a distance of shoreline retreat due to sea level rise similar to that predicted using the Bruun rule for minimal retreat less than 30 m, but the difference becomes substantial for more extensive decreases. The decrease in beach area is projected for different sea level rises based on four Representative Concentration Pathway (RCP) scenarios from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The decrease in beach area becomes more severe for the RCP8.5 scenario, and the proposed method predicts that a third of current sandy beaches in Japan will disappear. The extent of the decrease depends not only on the sea-level-rise scenario but also on the SLR projection model. [ABSTRACT FROM AUTHOR]

In coastal and insular regions, both climatic and sea-level changes during the Pleistocene had great influence on the population sizes and/or ranges of terrestrial animals. We investigated the intraspecific phylogeography of the Japanese ratsnake (Elaphe climacophora) to examine the differences in demographic patterns between regions with different degrees of impact during glacial periods on the Japanese Archipelago. We show that the population size of E. climacophora decreased greatly in northern Japan during glacial periods, and that it survived at least the last glacial period even in the northernmost area of Japan, Hokkaido. In south-western Japan, in contrast, the range of E. climacophora expanded during the early stage of the last glacial period when additional terrestrial habitats emerged because of sea-level fall. Subsequently, however, the population size contracted in south-western Japan because of climate cooling until the last glacial maximum. Thus, the historical demography of E. climaciphora differed considerably between northern and south-western Japan. The demographic pattern was also different even in the same region, south-western Japan, depending on the degree of global cooling during the last glacial period. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2 ) is one of the main sources of global warming, rising sea levels, and frequent outbreaks of extreme weather. China is now one of the largest energy consumer and CO 2 emitters in the world. As one of China's economic centers, Shanghai city has a perfect industrial system with large industrial scale. The industrial sector is an energy– and emission–intensive industry, which contributes the significant part of CO 2 emissions in Shanghai city. Therefore, an in–depth investigation of the main driving forces of CO 2 emissions in the industrial sector is essential to reduce CO 2 emissions in the city. This study uses Vector Autoregressive model to analyze the main factors causing the increase in CO 2 emissions in the industrial sector. The results show that economic growth leads to an increase in CO 2 emissions in the short run, but is conducive to reducing CO 2 emissions in the long run, due to the differences in fixed–asset investment and export trade. Energy consumption structure leads to a growing CO 2 emissions in the short term, and is beneficial to mitigate CO 2 emissions in the long term, owing to the gradual optimization of energy consumption structure. However, urbanization helps to reduce CO 2 emissions in the short term, but leads to an increase in CO 2 emissions in the long term, because of urban real estate and infrastructure construction investments as well as vehicle use. Energy efficiency leads to an increase in CO 2 emissions both in the short and long run since the scale effect exceeds the technical effect. Industrial structure produces a positive effect in the short run, but the impact is gradually narrowing in the long run. [ABSTRACT FROM AUTHOR]

Simulated signals from Global Navigation Satellite Systems (GNSS), reflected off the sea surface and received aboard low Earth orbiting satellites, have been used to derive sea surface height (SSH) and assimilated into an ocean model in an Observing System Simulation Experiment (OSSE). The experimental approach is named GNSS Reflectometry (GNSS-R), which was proposed for the International Space Station (ISS). This scientific experiment was conducted in the frame of the ESA mission called “ G NSS R E flectometry, R adio O ccultation and S catterometry aboard the International Space Station” (GEROS-ISS). In this study, three sources of uncertainties of the planned GNSS-R altimeter are considered by the GNSS-R simulator: the troposphere, the ionosphere, and a noise term. An ensemble optimal interpolation (EnOI) data assimilation system is set up for an eddy-resolving HYbrid Coordinate Ocean Model (HYCOM) of the South China Sea (SCS), and two data assimilation runs are performed from the 18th June to the 31st July 2014 with and without GNSS-R. In the run assimilating GNSS-R, the measurements come in addition to traditional Sea Level Anomalies (SLA) from present-day altimeters. In spite of the lower precision of individual GNSS-R retrievals, the results obtained in July show an overall improvement of the Root Mean Squared Difference (RMSD) by 14%, compared to traditional altimeter data only. Considering the crossing of Typhoon Rammasun through the SCS, the GNSS-R data improve the realism of the three largest eddies. The temperature sections along the typhoon track show large differences in the upper 200 m depths in excess of 1 °C near the shelf break. Finally, diagnostics of Degree of Freedom for Signal (DFS) provide a quantitative Impact Factor (IF) of the GNSS-R altimetry data over the conventional altimeter data. On average in July, the IF is low (<5%), but for the period of the typhoon it reaches values over 20%. This indicates the complementary of the GNSS-R altimetry data to the present observing system, especially in filling the gaps of the traditional altimeters. [ABSTRACT FROM AUTHOR]

Fine-grained sediments in southern Finland were deposited during the retreat of the continental Fennoscandian ice-sheet at around 13,000 cal BP, leaving subsequent ice-contact deposits and postglacial lake and, finally, the modern brackish water Baltic Sea basin (BSB). As a result of the strong glacioisostatic land uplift of the region, these sediments today lie above sea-level in coastal Finland. The recent expansion of cities to locations where superficial sediments are more challenging for construction purposes has increased the need for comprehensive understanding of the properties and geometry of these fine-grained superficial deposits. Commonly used site-specific lithostratigraphical characteristics of clayey deposits run the risk of ambiguous correlation between sites because of different types of postglacial depositional settings. The present study applies an allostratigraphical approach to classify late- and postglacial clayey deposits using examples from four sedimentary basins in the vicinity of the city of Espoo along the southern coast of Finland. This entails a reinterpretation of 17 core logs collected during the period 2006-2009 and reported in earlier studies, combined with examination of five new cores collected in 2016 coupled with borehole measurements of resistivity-temperature and electrical resistivity tomography (ERT). Physical proxies and sediment characteristics demonstrate that grey postglacial lacustrine silty (Ancylus Lake) clay is truncated at the top by an undulating erosional surface (unconformity), which is covered by a silt to sand layer a few centimetres thick that has a gradual-bioturbated upper contact to the greenish-grey brackish water (Litorina Sea) mud. Sediments above and below the unconformity are intensely bioturbated, and black mottling of Fe-monosulphide is observed in the brackish water mud. Evidently, this unconformity is of high engineering-geological significance because the organic-rich brackish water mud has a poorer bearing capacity and higher abundance of sulphide minerals that form sulphuric acid upon oxidation. It is demonstrated that this unconformity is spatially well recognised and provides a key stratigraphic marker for wider and more accurate comparison between sites with fine-grained deposits in the Helsinki metropolitan area and potentially in other urban areas in the northern Baltic Sea region. [ABSTRACT FROM AUTHOR]

Having great impacts on human lives, global warming and associated sea level rise are believed to be strongly linked to anthropogenic causes. Statistical approach offers a simple and yet conceptually verifiable combination of remotely connected climate variables and indices, including sea level and surface temperature. We propose an improved statistical reconstruction model based on the empirical dynamic control system by taking into account the climate variability and deriving parameters from Monte Carlo cross-validation random experiments. For the historic data from 1880 to 2001, we yielded higher correlation results compared to those from other dynamic empirical models. The averaged root mean square errors are reduced in both reconstructed fields, namely, the global mean surface temperature (by 24-37%) and the global mean sea level (by 5-25%). Our model is also more robust as it notably diminished the unstable problem associated with varying initial values. Such results suggest that the model not only enhances significantly the global mean reconstructions of temperature and sea level but also may have a potential to improve future projections. [ABSTRACT FROM AUTHOR]

There is a pressing need to find ways to communicate information about climate change effectively and in terms that resonate with diverse audiences. We conducted a survey-experiment to evaluate how textual and visual frames that highlight coastal flooding in two major US cities as a result of future sea level rise shape individuals’ perceptions about the effects on coastal communities, concern for these places, and belief in climate change’s existence. We build on extant literature by focusing on the impact of an understudied frame using animated maps that illustrate future flooding that will occur as global temperatures rise. We find that exposure to such messages increases perceptions that sea level rise will have negative impacts on coastal communities, concern for these communities, and belief in climate change. [ABSTRACT FROM AUTHOR]

Designing decision analytical models requires making choices that can involve a range of trade-offs and interactions between epistemic and ethical considerations. Such choices include determining the complexity of a model and deciding what types of risk will be assessed. Here, we demonstrate how model design choices can involve trade-offs between the epistemic benefits of representational completeness and simplicity, which interact with ethical considerations about fairness and human life. We illustrate this point by focusing on modeling studies that assess flood risks in New Orleans, Louisiana. Addressing the ethical and epistemic implications of model design choices can help clarify the scope of factors necessary to inform ethically sound and economically efficient decision-making. [ABSTRACT FROM AUTHOR]

The hydraulic diffusivity gives a measure of diffusion speed of pressure disturbances in groundwater system; large values of hydraulic diffusivity lead to fast propagation of signals in aquifer. This research provides a novel design and derives spectral representation to determine hydraulic diffusivity using spectral analysis of groundwater levels coupled with time-dependent boundary adjacent to marine system and no flow boundary in aquifer system. To validate the proposed method, water levels of fluctuated boundary and groundwater well in a sandy confined aquifer were collected. The hydraulic diffusivity is then obtained by an inverse process in the non-linear complex form of spectral relationship. The method essentially is constructed on the conceptual design of natural forcing transmitted in large aquifer. It is unlike the conventional field pumping test which is only used to determine hydraulic properties of groundwater in small range around the well. Hydraulic diffusivity of the confined aquifer is determined using real observation and then checked by comparing to the published range. It suggests that without local aquifer test to estimate hydraulic diffusivity in a coastal aquifer using spectral representation with its relevant flow system and boundary has become feasible. [ABSTRACT FROM AUTHOR]

Unique location in the land-sea interface makes mangrove ecosystems most vulnerable to the impacts of predicted sea level rise due to increasing anthropogenic CO 2 emissions. Among others, carbon sink function of these tropical ecosystems that contribute to reduce rising atmospheric CO 2 and temperature, could potentially be affected most. Present study was undertaken to explore the extent of impact of the predicted sea level rise for the region on total organic carbon (TOC) pools of the mangrove ecosystems in Negombo estuary located on the west coast of Sri Lanka. Extents of the coastal inundations under minimum (0.09 m) and maximum (0.88 m) sea level rise scenarios of IPCC for 2100 and an intermediate level of 0.48 m were determined with GIS tools. Estimated total capacity of organic carbon retention by these mangrove areas was 499.45 Mg C ha − 1 of which 84% (418.98 Mg C ha − 1 ) sequestered in the mangrove soil and 16% (80.56 Mg C ha − 1 ) in the vegetation. Total extent of land area potentially affected by inundation under lowest sea level rise scenario was 218.9 ha, while it was 476.2 ha under intermediate rise and 696.0 ha with the predicted maximum sea level rise. Estimated rate of loss of carbon sink function due to inundation by the sea level rise of 0.09 m is 6.30 Mg C ha − 1 y − 1 while the intermediate sea level rise indicated a loss of 9.92 Mg C ha − 1 y − 1 and under maximum sea level rise scenario, this loss further increases up to 11.32 Mg C ha − 1 y − 1 . Adaptation of mangrove plants to withstand inundation and landward migration along with escalated photosynthetic rates, augmented by changing rainfall patterns and availability of nutrients may contribute to reduce the rate of loss of carbon sink function of these mangrove ecosystems. Predictions over change in carbon sequestration function of mangroves in Negombo estuary reveals that it is not only affected by oceanographic and hydrological alterations associated with sea level rise but also by anthropogenic processes, therefore the impacts are site specific in terms of distribution and magnitude. [ABSTRACT FROM AUTHOR]

Different multidisciplinary data concerning the paleodynamics of sea-level variations in the Caspian and Black seas are controversial in some aspects. There are at least three paradoxes that are discussed in the paper. The Paradox No. 1 relates to the Early and Late Khvalynian transgressions that occurred in the CS during the second part of MIS 3 (∼35–25 ka BP) and the Late Glacial epoch (∼17–12 ka BP), respectively. It is unclear what the main source or sources of water were that caused them. Paradox No. 2 emerges from the comparison of climate events and transgressive-regressive cycles in the Caspian Sea and the Black Sea. It implies that large sea-level anomalies occurred in accordance with global climate changes (because they are influenced by climate variations). However, other (not so long-lived) sea-level fluctuations are poorly correlated with climate events. The question is why climatically-induced sea-level changes did not follow climatic variations. Paradox No. 3 concerns the contradiction between the massive water discharge from the Black Sea into the Sea of Marmara via the Bosphorus Strait and the Black Sea level fluctuations in the Latest Pleistocene-Holocene that could not exist simultaneously. It is shown that Paradox No. 2 has been solved, at least on conceptual level. Solutions to Paradoxes No. 1 and No. 3 are still lacking: further geological and geochronological evidence as well as climate simulation are required. Formulation of solutions for these paradoxes should make a major contribution not only to the problems of the Caspian and Black seas’ paleogeography, but also provide help in explaining the reasons for inadequate simulation of regional climate changes. This is important in the context of the development of models for future climate prediction. [ABSTRACT FROM AUTHOR]

The analysis of seismic-acoustic profiles and drilling data from the Northern Caspian showed the climatic events are quite distinguishable in the Upper Pleistocene sedimentary sequence. The climatic events of the first half of Late Pleistocene (MIS 5) resulted in the onset of two warm-water transgressive basins – Late Khazarian and Hyrcanian ones. Though cooler than at the late Khazarian transgression, the climate during the Hyrcanian time was attributable to interglacial one. As the glacial stage MIS 4 approached its maximum under conditions of a dry and cold climate the Hyrcanian sea basin regressed. The Atelian regression of the Caspian Sea corresponded to MIS 4 stage and to the initial phases of the MIS 3 interstadial warming. The development of the global interstadial warming led to a considerable increase in the surface runoff from the catchment and resulted in the rising of the Atelian lake level and the onset of the first phase of the Khvalynian transgression. The sea level rising was interrupted at the time of maximum cooling and aridization at MIS 2 and resumed when the ice sheet was decaying. The conspicuous climatic events known as warm phases of Bølling and Allerød promoted the ice sheet melting along with thawing of permafrost, the latter having been widespread in the Volga drainage basin. All the above contributed to the Khvalynian transgression. The ‘chocolate’ clays were accumulated in the Volga estuary, as well as in depressions of the Pre-Khvalynian topography. Phases of a noticeable cooling known as the Oldest, Older and Younger Dryas marked by a decrease in the runoff volume from the Caspian drainage basin are correlated with regressive stages in the Khvalynian basin history. The Khvalynian came to its end at the time of the first sharp warming that resulted in the rise of the Caspian level and is generally taken as marking the Pleistocene/Holocene boundary. The Mangyshlakian regression is dated to the Holocene and was essentially a response of the Caspian Sea to the increase in the climate continentality during the Boreal period. [ABSTRACT FROM AUTHOR]

Based on the hindcast data from third-generation wave model WAVEWATCH III, this study presents a notable interannual variability of significant wave height in the northern South China Sea. As indicated by the empirical orthogonal function analysis result of the significant wave height during 1976-2005, the first mode of this analysis captures a monopole structure with maximum amplitude in the southwestern Luzon Strait. Power spectrum analysis of the first empirical orthogonal function time series indicates that the significant wave height peaks at 2.67 and 8 year periods in the northern South China Sea. The first-time series had good correlation with El Niño events, with a correlation coefficient of -0.58. By comparing frequency and total duration of the intense tropical cyclones with the significant wave height in the northern South China Sea, it is revealed that the two were associated during 1978-1998 and that the recent increase of the significant wave height is due to the increase in total duration of intense tropical cyclones during 1999-2005. The sea level pressures also support the interannual variability of significant wave height in the northern South China Sea. [ABSTRACT FROM AUTHOR]

Persistent pressures from water-related threats – sea-level rise, soil and water salinization, and flooding due to embankment overtopping and failure – have made the West Bengal Sundarbans a challenging place to live, and effects of global climate change will only worsen conditions. Four alternative policy directions are examined: business as usual; intensive rural development; short-term out-migration of residents; and embankment realignment and facilitation of voluntary, permanent out-migration. The last of these is the recommended approach. Study findings have informed ongoing deliberations to build consensus on future policy directions for reducing the region’s vulnerability to natural disasters. [ABSTRACT FROM PUBLISHER]

Sea-level rise, as a result of global warming, may lead to more natural disasters in coastal regions where there are substantial aggregations of population and property. Thus, this paper focuses on the impact of sea-level rise on the recurrence periods of extreme water levels fitted using the Pearson type III (P-III) model. Current extreme water levels are calculated using observational data, including astronomical high tides and storm surges, while future extreme water levels are determined by superposing scenario data of sea-level rise onto current extreme water levels. On the basis of a case study using data from Shandong Province, China, results indicated that sea-level rise would significantly shorten the recurrence periods of extreme water levels, especially under higher representative concentration pathway (RCP) scenarios. Results showed that by the middle of the century, 100-year current extreme water levels for all stations would translate into once in 15-30 years under RCP 2.6, and once in ten to 25 years under RCP 8.5. Most seriously, the currently low probability event of a 1000-year recurrence would become common, occurring nearly every 10 years by 2100, based on projections under RCP 8.5. Therefore, according to this study, corresponding risk to coastlines could well be increase in future, as the recurrence periods of extreme water levels would be shortened with climate change. [ABSTRACT FROM AUTHOR]

Chen, L. and Wang, W., 2017. Ecophysiological responses of viviparous mangrove Rhizophora stylosa seedlings to simulated sea-level rise. As the only forests situated at the transition between land and sea, mangrove forests constitute one of the first ecosystems vulnerable to rising sea level. When sea-level rises, plants are exposed to increased salinity, as well as tidal flooding. The responses of mangrove forests to changing sea levels depend on the synergistic effects of tidal flooding and salinity on plants, especially plants at the seedling stage. Therefore, the aims of this paper were to assess the ability of viviparous mangrove Rhizophora stylosa Griff. seedlings to withstand tidal flooding given different seawater salinities, as well as to investigate the effects of tidal flooding and salinity on plant growth. To accomplish this, a mesocosm experiment was initiated to examine the synergistic effects of tidal flooding and salinity on the growth and physiology of R. stylosa samples subjected to seven tidal flooding times (0, 2, 4, 6, 8, 10, and 12 h simulated semidiurnal tide, twice daily) and two levels of water salinity (15 and 30 PSU [practical salinity units]) over the course of 100 days. Throughout the experimental period, R. stylosa seedlings exhibited the traits of flood-tolerant plants, including such mechanisms as high stem growth rate and leaf assimilation rate, as well as efficient utilization of carbohydrate reserves stored in hypocotyls of seedlings. The growth and physiological responses of R. stylosa seedlings were significantly affected by both salinity and flooding time. However, elevated salinity had less effect on growth and metabolism than simulated sea-level rise by the increase of flooding time. From these results, it can be concluded that R. stylosa at higher salinity exhibits competitive dominance and thus good adaptation of seedlings to future predicted rise in sea level, which could presumably result in niche shifting. [ABSTRACT FROM AUTHOR]

Coastal flood risk will likely increase in the future due to urban development, sea-level rise, and potential change of storm surge climatology, but the latter has seldom been considered in flood risk analysis. We propose an integrated dynamic risk analysis for flooding task (iDraft) framework to assess coastal flood risk at regional scales, considering integrated dynamic effects of storm climatology change, sea-level rise, and coastal development. The framework is composed of two components: a modeling scheme to collect and combine necessary physical information and a formal, Poisson-based theoretical scheme to derive various risk measures of interest. Time-varying risk metrics such as the return period of various damage levels and the mean and variance of annual damage are derived analytically. The mean of the present value of future losses (PVL) is also obtained analytically in three ways. Monte Carlo (MC) methods are then developed to estimate these risk metrics and also the probability distribution of PVL. The analytical and MC methods are theoretically and numerically consistent. A case study is performed for New York City (NYC). It is found that the impact of population growth and coastal development on future flood risk is relatively small for NYC, sea-level rise will significantly increase the damage risk, and storm climatology change can also increase the risk and uncertainty. The joint effect of all three dynamic factors is possibly a dramatic increase of the risk over the twenty-first century and a significant shift of the probability distribution of the PVL towards high values. In a companion paper (Part II), we extend the iDraft to perform probabilistic benefit-cost analysis for various flood mitigation strategies proposed for NYC to avert the potential impact of climate change. [ABSTRACT FROM AUTHOR]